This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The specific aim of this pilot proposal is to determine whether knockdown of Ldhc in the baboon testis can disrupt sperm function and serve as the basis for a male contraceptive technology. Goldberg and co-workers (Odet et al., Biol Reprod. 2008 Jul;79(1):26-34. Epub 2008 Mar 26) were successful in targeting disruption of the Ldhc gene in mice. Sperm from these males were unable to fertilize eggs. This observation validates LDHC as a target for contraceptive development. Our collaborator, Dr. Mark Saltzman, Yale University has been able to demonstrate that siRNA can be utilized in a biodegradable delivery system to knock down gene expression (personal communication) suggesting that targeting Ldhc in this way should be an effective male contraceptive. There is an obvious need for innovative contraceptive technology for men.